According
to an ancient tradition, allegelly dating back to Sinai, puberty is
established by the growth of at least two pubic hairs. The Talmud
estimated that the appearance of pubic hair generally coincides with
the beginning of the fourteenth year of a male and the thirteenth year
of a female. The determining condition of adulthood is puberty, not
age. In the absence of pubic development one remains a minor. On the
other hand, pubic symptoms prior to the age of twelve or
thirteen are considered premature abnormalities which do not signify
adulthood. (...) The peak of intellectual development, according to the Talmud, is reached at the age of twenty in both sexes.The Biblical and historical background of Jewish customs and ceremonies, by Abraham P. Bloch

יְחֶזְקֵאל טזז
רְבָבָה, כְּצֶמַח הַשָּׂדֶה נְתַתִּיךְ, וַתִּרְבִּי וַתִּגְדְּלִי,
וַתָּבֹאִי בַּעֲדִי עֲדָיִים: שָׁדַיִם נָכֹנוּ וּשְׂעָרֵךְ צִמֵּחַ,
וְאַתְּ עֵרֹם וְעֶרְיָה. Ezekiel 16 7 And
I helped you to thrive like a plant in the field. You grew up and
became a beautiful jewel. Your breasts became full, and your body hair
grew, but you were still naked..

"The
prophet has arrived at the time at which the child grew up to maturity.
God preserved the life of the infant which must without His help have
died Ezekiel 16:6; and the child grew up to womanhood, but was still
desolate and unprotected. This represents the sojourn in Egypt, during
which the people increased, but were not bound, as a nation, to God by
a covenant." Barnes' Notes on the Bible:

The ancient Romans on sexual maturity

Virgo pubescens, et nux matura rubescens,illa quidem tangi vult, haec de stipite frangi.A virgin reaching puberty (literally 'getting pubes') and a ripe nut becoming red,the former certainly wants to be touched, the latter wants to be taken from the branch.

The ancient Roman common wisdom recalled aboveis reflected in many modern languages:

"Apart from love poetry, the word PUELLA defines the period of a girl's life from infancyto the age of menarche, a time fixed in Julian law as 12 years old, the minimal age at which agirl could legally become a wife. Cases of aristocratic girls being married at a much earlier agewere widespread before the passage of the Lex Julia de maritandis ordinibus in 18 BCE.

Even after Augustus limited the engagement period to two years, elite parentsbetrothed prepubescent daughters to men who were sometimes underage and frequentlymuch older, divorced or widowed. The imperial family was particularly guilty: Vipsania wasengaged to Tiberius when she was 2 years old and he was 7; the Emperor Claudius’ daughter Octavia was first betrothed to L. Junius Silanus as aninfant; when that engagement was broken by her stepmother, she was married at 11 to heradopted brother Nero. Various and multiple motives led nobles to commit their daughters tomarriage before they were capable of understanding or giving consent. Chief among them wasthe desire for forging family alliances and improving sociopolitical status, though someconsideration was given to finding a man of good character, especially during the classicalperiod. Finally, paternal concern for a young girl's virginity and filial obedience made earlymarriage desirable. However, unlike female children born to the poor who were oftenunwanted and abandoned, elite daughters were not begrudged family resources and attention.Prominent fathers showed pride in and love for their daughters, educating and encouragingthem in various ways –Matrimonium

Our predecessors did not neglect sexual urges awakening in pubertal children. Instead, they protected the most vulnerable ones against sexual abuse and its grave effects.

Although definitely NOT mature, pubertal and adolescent boys and girls are sexual entities who nowadays are being exposed on an unprecedented scale to hazards never seen before.

rapidly increasing number of victims of so called 'digital abuse' acting as role models for their peers when free access of pedophiles and ephebophiles to unlimited number of children and adolescentsby means of digital media (text, photo, video, audio) and the Internet beyond parental control offers
a comfortable and untroubled playground for sexual predators, sex
obsessed maniacs, sexual deviants who dehumane, humiliate, and imprint
their deviances on our children's minds. see: Depiction of virginity

!!!

rise of militant anti-religiosity, militant secularismspreading all over the worldwhen in place of God are being put simple pleasuresmediated by brain chemicals that are triggered by biological mechanisms easily commercialized for
the sake of financial tycoons and their puppets and agents of influence in governments, mainstream media, pop culture, academia, and other opinion-making bodies.